Commit 3cbeb524 authored by Antonio Borneo's avatar Antonio Borneo Committed by Paolo Bonzini
Browse files

hw/i386: add device tree support 



With "-dtb" on command-line:
- append the device tree blob to the kernel image;
- pass the blob's pointer to the kernel through setup_data, as
  requested by upstream kernel commit da6b737b9ab7 ("x86: Add
  device tree support").

The device tree blob is passed as-is to the guest; none of its
fields is modified nor updated. This is not an issue; the kernel
commit above uses the device tree only as an extension to the
traditional kernel configuration.

To: "Michael S. Tsirkin" <mst@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
To: Richard Henderson <rth@twiddle.net>
To: Eduardo Habkost <ehabkost@redhat.com>
Cc: qemu-devel@nongnu.org
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarAntonio Borneo <borneo.antonio@gmail.com>
Message-Id: <1459973054-2777-1-git-send-email-borneo.antonio@gmail.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent fd9a3048

hw/i386/pc.c

+46 −0
Original line number Diff line number Diff line
@@ -812,11 +812,26 @@ static long get_file_size(FILE *f) 
    return size;

}



/* setup_data types */

#define SETUP_NONE     0

#define SETUP_E820_EXT 1

#define SETUP_DTB      2

#define SETUP_PCI      3

#define SETUP_EFI      4



struct setup_data {

    uint64_t next;

    uint32_t type;

    uint32_t len;

    uint8_t data[0];

} __attribute__((packed));



static void load_linux(PCMachineState *pcms,

                       FWCfgState *fw_cfg)

{

    uint16_t protocol;

    int setup_size, kernel_size, initrd_size = 0, cmdline_size;

    int dtb_size, setup_data_offset;

    uint32_t initrd_max;

    uint8_t header[8192], *setup, *kernel, *initrd_data;

    hwaddr real_addr, prot_addr, cmdline_addr, initrd_addr = 0;
@@ -824,8 +839,10 @@ static void load_linux(PCMachineState *pcms, 
    char *vmode;

    MachineState *machine = MACHINE(pcms);

    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);

    struct setup_data *setup_data;

    const char *kernel_filename = machine->kernel_filename;

    const char *initrd_filename = machine->initrd_filename;

    const char *dtb_filename = machine->dtb;

    const char *kernel_cmdline = machine->kernel_cmdline;



    /* Align to 16 bytes as a paranoia measure */
@@ -988,6 +1005,35 @@ static void load_linux(PCMachineState *pcms, 
        exit(1);

    }

    fclose(f);



    /* append dtb to kernel */

    if (dtb_filename) {

        if (protocol < 0x209) {

            fprintf(stderr, "qemu: Linux kernel too old to load a dtb\n");

            exit(1);

        }



        dtb_size = get_image_size(dtb_filename);

        if (dtb_size <= 0) {

            fprintf(stderr, "qemu: error reading dtb %s: %s\n",

                    dtb_filename, strerror(errno));

            exit(1);

        }



        setup_data_offset = QEMU_ALIGN_UP(kernel_size, 16);

        kernel_size = setup_data_offset + sizeof(struct setup_data) + dtb_size;

        kernel = g_realloc(kernel, kernel_size);



        stq_p(header+0x250, prot_addr + setup_data_offset);



        setup_data = (struct setup_data *)(kernel + setup_data_offset);

        setup_data->next = 0;

        setup_data->type = cpu_to_le32(SETUP_DTB);

        setup_data->len = cpu_to_le32(dtb_size);



        load_image_size(dtb_filename, setup_data->data, dtb_size);

    }



    memcpy(setup, header, MIN(sizeof(header), setup_size));



    fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, prot_addr);